The present invention relates to an adjustable device for centering high-speed rotating bars in automatic magazines interlocked with lathes, and to a magazine for use with such a device.
In the known art automatic magazines sequentially loading and feeding bars to lathe mandrels are well known. These magazines can be of the type feeding single-mandrel or multi-mandrel lathes.
One of the major problems in these magazines is how to enable free rotation of the bars that may be fed also at high and very high speed, without vibrations along the bar taking place. Solution of this problem is made still more difficult, due to the fact that the diameter of the bars to be fed can vary within a very wide range, whereas the pusher moving the bar towards the lathe has a fixed diameter greater than that of the fed bar.
In the known art, magazines have been proposed which have guides extended along the bar path, which guides for instance consist of a plurality of circumferential aligned segments to form a cylindrical duct in which the bar and the related pusher run. The cylindrical duct has the same diameter as the pusher to enable passage thereof. The bar fed to the guide therefore has a side clearance which may be even very high.
Although the bar is supported at the leading end by the lathe mandrel and at the trailing end by the pusher clamp (in turn guided by the cylindrical duct), when distance between the leading and trailing support point is great, the bar has a tendency to bend and its quick rotation causes vibrations affecting the lathe, thereby impairing operation of the lathe itself.
It is a general object of the present invention to obviate the above mentioned drawbacks by providing a centering device that can be easily adjusted depending on the diameter of the used bar, so as to support it in an efficient manner at points intermediate its ends and also damping possible vibrations, while at the same time enabling passage of a pusher of bigger diameter. It is a further object of the invention to provide a magazine for use with such a device.